Background: Previously we have reported that patients with rheumatoid arthritis (RA) obtained a significant reduction in disease activity by adopting a Mediterranean-type diet. The present study was carried out to investigate the antioxidant intake, the plasma levels of antioxidants and a marker of oxidative stress (malondialdehyde) during the study presented earlier.

Objective: To examine diet costs in relation to dietary quality and socio-economic position, and to investigate underlying reasons for differences in diet costs. Design: Dietary intake was assessed by a 4 d food diary and evaluated using the 2005 Healthy Eating Index (HEI). National consumer food prices collected by Statistics Sweden and from two online stores/supermarkets were used to estimate diet costs. Setting: Sweden. Subjects: A nationally representative sample of 2160 children aged 4, 8 or 11 years. Results: Higher scores on the HEI resulted in higher diet costs and, conversely, higher diet costs were linked to increased total HEI scores. Children who consumed the most healthy and/or expensive diets ate a more energy-dilute and varied diet compared with those who ate the least healthy and/or least expensive diets. They also consumed more fish, ready meals and fruit. Regression analysis also linked increased food costs to these food groups. There was a positive, but weak, relationship between HEI score and diet cost, parental education and parental occupation respectively. Conclusions: Healthy eating is associated with higher diet cost in Swedish children, in part because of price differences between healthy and less-healthy foods. The cheapest and most unhealthy diets were found among those children whose parents were the least educated and had manual, low-skill occupations. Our results pose several challenges for public health policy makers, as well as for nutrition professionals, when forming dietary strategies and providing advice for macro-and microlevels in society.

The aim of this research was to examine the cost of a diet generally regarded as healthy, a Swedish version of the Mediterranean diet, and to compare it with the cost of an ordinary Swedish diet. A total of 30 individuals provided detailed dietary data collected in a randomized intervention study, examining the effect of dietary change to a Mediterranean‐style diet in patients with rheumatoid arthritis (Mediterranean group, n = 16, control group, n = 14). The data, covering 1‐month dietary intake, were examined with three different diet quality indicators to see whether the Mediterranean group consumed a healthier diet than the control group. All diet quality indicators showed that the Mediterranean group consumed a healthier diet than the control group. Consumer food prices were used to analyse the cost of the different diets. In immediate consumer cost terms, eating a healthier diet was more expensive when differences in energy intake were discounted. However, non‐energy adjusted costs showed no significant difference between the groups. Hence, if one of the reasons for choosing a healthier diet is to achieve weight loss – by consuming less energy – it is possible that healthier eating is not more expensive.

Objectives: The aim of the study was to validate a diet history interview (DHI) method and a 3-day activity registration (AR) with biological markers. Subjects and study design: The reported dietary intake of 33 rheumatoid arthritis patients (17 patients on a Mediterraneantype diet and 16 patients on a control diet) participating in a dietary intervention study was assessed using the DHI method. The total energy expenditure (TEE), estimated by a 3-day AR, was used to validate the energy intake (EI). For nine subjects the activity registration was also validated by means of the doubly labelled water (DLW) method. The excretion of nitrogen, sodium and potassium in 24-h urine samples was used to validate the intake of protein, sodium and potassium. Results: There was no significant difference between the EI and the TEE estimated by the activity registration or between the intake of protein, sodium and potassium and their respective biological markers. However, in general, the AR underestimated the TEE compared to the DLW method. No significant differences were found between the subjects in the Mediterranean diet group and the control diet group regarding the relationship between the reported intakes and the biological markers. Conclusion: The DHI could capture the dietary intake fairly well, and the dietary assessment was not biased by the dietary intervention. The AR showed a bias towards underestimation when compared to the DLW method. This illustrates the importance of valid biological markers.

Omega-3 fatty acids in adequate doses may have the capacity to decrease the disease activity of AS. However, larger and better controlled studies are needed before any further conclusions can be made on the extent of this capacity.